Starfish is a member of phylum Echinodermata, which is characterised by pentagonal star-like body, hollowarms (containing gonads) and presence of tube feet, arranged in 2−4 rows in open amhulacral grooves. Porifera : Leucosolenia, Euspongia, Spongilla. Coelenterata : Hydra, Physalia, Obelia. Arthropoda: Scorpion, Limulus, Palaemon, Daphnia.